covdep = function(cov_dep, ...) {
	# name=names(cov_dep)
	cov_dep$V2 = cov_dep$V2 / 100
	xlim=c(0, max(cov_dep$V1)+1)
	ylim=c(0, 1)
	vline=(xlim[1]+1):(xlim[2]-1)
	hlineby=.1
	hline=seq((ylim[1]-hlineby), (ylim[2]-hlineby), hlineby)


	# pdf("1.cov.vs.dep.pdf", width=12, height=3)
	pdf("1.cov.vs.dep.pdf", width=12, height=9)
	par(pch=18, lwd = .2, ann=F, xaxs='i', yaxs='i')
	
	plot(cov_dep$V1, cov_dep$V2, type='o', xlim=xlim, ylim=ylim, col='blue', pch=0, lwd=.4)
	abline(v=vline, h=hline, lty=3, col='gray')
	
	title(main="The fraction of the genome with the >= 1x coverage vs. the mean sequencing depth", xlab="Mean sequencing depth", ylab="Fraction of the genome", ...)
	
	dev.off()
}